Physico-Chemical Studies of the Binding of Metal Ions with Soybean Protein. Part II. pH-Metric Studies in the Presence of Cu ++ and Cd++

Department of Chemistry, University of Roorkee, Roorkee

Manuscript received 14 June 1974; revised 23 September 1974; accepted 23 September 1974

The binding of Cu++ and Cd-H to soybean protein has been investigated \(p\)H-metrically. Interaction of these ions takes place with the carboxyl as well as the imidazole group of the protein molecule. The values of log K for metal carboxyl binding are found to be 2.03 and 1.85 for Cu⁺⁺ and Cd⁺⁺ respectively. These values favour comparably with the log K values of the first association constants of the interaction between corresponding metal and acetate group. The log K values for metal-imidazole binding are found to be 2.34 and 2.08 for Cu⁺⁺ and Cd⁺⁺ respectively.